Tool retainer



June 24, 1930. H. c. GusTAFsON TOOL RETAINER Filed Oct. 12. `1926 jm/5. @5% i A www I Patented June 24, 1930 UNITED STATES PATENT OFFICE IIJALMER C. GUSTAFSON, OF DENVER, COLORADO, ASSIG-NOR, BY ASSTGNMENTS, T0 THE GARDNER-DENVER COMPANY, OF QUINCY, ILLINOIS, A CORPORATION OF DELAVARE TOOL RETAINER Application tiled October 12, 1926.

The present invention relates to tool retainers for rock drills and the like, the object being to provide a new device of the general type disclosed in my prior Patent No. 1,580,599,01 Apen is,

The principal object is to provide a structure that is more easily operated to permit the removal of the tool.

In the accompanying drawings Figure 1 is a view of a fluid operated tool with the tool retainer in place thereon and shown in section, with the retaining dogs 1n their operative positions,

Figure 2 is a view of the retainer showing the dogs in their inoperative relations,

Figure 3 is a front elevation on an enlarged scale of the dogs,

Figure i is a side elevation of the same,

Figure 5 is a perspective view.

In the embodiment disclosed, a hammer drill is shown at 6, and contains the usual tool holder in the form of a chuck 7. A hammer piston is illustrated at 8, and is located behind the bore or socket 9, adapted to receive a drill steel or other tool, designated 10. This steel is provided with the usual collar 11. Fitted on the front end oi' the drill barrel or head 6 is a hood or housing 12, the portion oi? said hood or housing that fits over the head being split, as shown at 13, so that it may be contracted. A tie bolt 14 serves to contract the said portion, and is preferably iitted into a transverse groove 15 formed in the head of the barrel. Consequently the hood is rigidly fixed to the tool. The front wall 1G ot said hood or housing is inturned, and is provided with an opening 17 ot sufficient size to permit the passage of the rear end of the steel 1() and its collar 11.k This wall has its inner face rounded, as illustrated at 18, forming pivot bearings, against which knuckle retaining dogs 19. These dogs are acurate in form, and tiare outwardly, their outer ends being rounded as illustrated at 20, so as to rotatably bear against the iaces 18. The inner ends of the dogs have overlapped toothed portions 21.

The rear ends of these dogs constitute shoulders 22, againSt which the collar 11 of Serial No. 141,197.

the steel abuts when the dogs are in their operative positions, as shown in Figure 1. These dogs furthermore have outstanding lugs 23 and 24 engaged in slots formed in the opposite sides of the hood. One of the lugs, as 24, is longer than the other and projects beyond the hood, forming a fingerpiece 2G. A coiled spring 27 is interposed between the inner ends of the lugs and the l'ront end of the barrel or head. This coiled spring is ot sutlicient diameter to permit the location therein of the collar 11 of the drill steel.

The inner portions ot the lugs against which the spring bears are designated 28, and these portions besides acting as seats for the spring which insures compression of the spring when the dogs are opened, as illustrated in Figure 2, also act as stops to Vlimit the amount ot opening movement ot' vthe jaws. In such opening movement the portions 28 strike the inner tace ot the hood substantially in the posit-ion shown in Figure 2, and thus stop the movement ol" the dogs before the teeth 21 pass out of inter-fitting relation.

Tt will be evident that with this construction a drill steel can be passed through the opening 17, and into the socket 9 of the chuck 7. The, collar 11 forces the dogs apart, and said dogs will seat against each other in advance of the collar. After its passage thereby the steel is thus automatically locked in place, but is permitted to have the necessary play. To release the steel, it is only necessary to move the lingerpiece 26 forwardly. This causes the tilting ot the dog carrying said finger-piece and moves inwardly the underlying teeth 21 of said dog. This correspondingly swings the other dog outwardly. Both dogs are therefore operated by the single finger-piece, which has been found a more convenient arrangement than the use of two finger-pieces, one on each dog` both of which must be moved simultaneously. In this case the lug` Q3 serves merely as a guide that prevents the displacement of the dog carrying it.

From the foregoing, it is thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled in the art. without further description, and it will he understood that various changes in the Asize. shape, proportion and lninor details ol'v eonstruction may be resorted to without departing from the spirit or sacrificing any ot the advantages of the invention.

\Vhat I claim, is:

1. A tool holder comprising a housing. a pair of tool-retaining dogs formed of substantially arcuate shaped walls and having journal bearings at the outer sides of their outer ends in the outer portion of the housing` the inner sides of the Walls abutting and having intertitting portions at the out-er ends of the dogs that insure their simultaneous movement away from each other, the inner ends of the dogs; havin@r laterally outstanding enlargements that abut against the inner face of the housing to limitthe movement of the dogs away from each other, and a spring bearing against the enlargements.

2. A tool holder comprising a housing that receives the tool, opposite cooperating tool retaining dogs comprising tool einbracing Walls having pivotal bearings at their outer end corners in the housing and having substantially flat inner abutting faces which when in abutting relation form a. space ot .sufficient area to permit the Afree longitudinal play of the tool. the adjacent portions of the dogs at their outer ends beyond said abutting faces havingr intertittingr portions that cause their simultaneous swinging movement away from each other.

In testimony whereof I allix my signin ture.

HJALMER C. GUTAFSON. 

